Socket and base for lamps



Feb. 4, 1969 R. P. FONTANA SOCKET -ND BASE FOR LAMPS Fired Jan. 27, 1967FIG. 1

FIG.. 3

FIG. 4

INVENToR RAYMOND PETER FONTANA IIIII AT TORNE S United States Patent O 8Claims ABSTRACT F THE DISCLOSURE A base for an electric lamp having apellet of resilient material protruding therefrom which engages the wallof the surrounding socket under pressure and prevents the lamp frombecoming loose in or detaching from the socket. The pellet of resilientmaterial also can Ibe used in the socket instead of the lamp base.

BACKGROUND OF THE INVENTION Field of the invention This inventionrelates to electric lamps and more particularly to a novel ibase and/orsocket for a lamp which prevents it from becoming loose in ordisengaging from its socket.

In some use applications of electric lamps, particularly where the lampis subjected to large amounts of vibration such as produced by closelylocated machinery or other similar equipment, a problem arises in thelamps becoming loose in and/ or falling out of their sockets. Thisproblem is more acute lwith lamps having screw type bases since thecontinuous threads of the lamp base and socket make it relatively easyfor the lamp to `become unscrewed from its socket.

It is of lcourse highly desirable to firmly hold an electric lamp withinits socket. Otherwise, the lamp can ibecome loose to a point where itbreaks the electrical contact with its socket and becomes inoperative orfalls completely out of the socket. The latter is, of course,particularly undesirable since it presents a safety hazard.

SUMMARY OF THE INVENTION The present invention relates to a novelconstruction of a lamp base and/ or socket which firmly holds a lampwithin its socket and prevents it from becoming loose. In accordancewith the invention, a pellet of flexible and compressible material isfixed to the lamp base and/ or socket. As the lamp is inserted into thesocket the pellet material is compressed between the walls of the lampbase and its socket. The force exerted by the pellet in tending toreturn to its original shape provides an additional force of substantialmagnitude acting to prevent the lamp from becoming loose in its socket.In a preferred embodiment of the invention used with a lamp having ascrew type base, the pellet is inserted ibetween two adjacent crests ofthe screw thread and its portion which lies inside of the base occupiesan area which is usually free of other parts in a conventional lamp.

It is therefore an orbject of the present invention to provide means forsecuring and holding an electric lamp in its socket.

A further object is to provide a lamp base having a pellet of resilientand compressible material held therein for engaging the wall of a socketto securely hold the lamp in the socket.

Another object is to provide a screw-type lamp base having a pellet ofresilient and compressible material held therein to securely hold thelamp in its socket.

Yet another object is to provide a socket for an electric lamp having apellet of compressible material held 3,426,314 Patented Feb. 4, 1969 onthe Wall thereof to securely engage a lamp base.

Other objects and advantages of the present invention will become moreapparent upon reference to the following specification and in theannexed drawings, in which,

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is an elevational view of aportion of an incandescent lamp and its base taken partly in section andshowing the subject invention;

FIG. 2 is a side view of the pellet shown mounted in the base of a lamp;

FIG. 3 shows the lamp of FIG. l screwed into the socket; and

FIG. 4 is a side elevational view in section showing a socket having apellet according to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT FIGS. 1 and 2 show a portion ofa conventional screwtype incandescent lamp having an outer glassenvelope 11. The bottom portion of the envelope is doubled over to forma reentrant stem 13 through which a pair of lament wires 15 and 17 pass.The stem 13 seals off the envelope 11 and the envelope is exhaustedthrough a tubulation (not shown) which is tipped off after manufacturingis completed.

The glass envelope 11 is held within a base 20 of electricallyconductive material by an amount of a suitalble adhesive 21 placedaround the bottom of the bulb. The base 20 has screw threads 22 thereon.In the conventional manner, filament wire 15 is connected at point 24 bysolder or `spot welding to the screw-threaded portion of the conductiveibase. The lower portion of the base has a lip 26 which holds a disc 27of insulating material and an electrically conductive contact member 28is located thereon. Filament wire 15 is connected to the contact 28. Thestructure heretofore described is entirely conventional.

As shown in FIG. l, there is an empty area in the base between itsbottom and the bottom of the envelope. A hole 30 is drilled or otherwiseformed, in the side wall of the base to communicate with the empty area.As shown, the hole is preferably made in the valley between two adjacentcrests Of the screw thread.

A pellet 35 of a suitable resilient and compressible material is mountedwithin the hole 30. The material for the pellet may be, for example,nylon or any other suitable material or synthetic material which has thenecessary temperature characteristics. One other suitable material forthe pellet is Teflon.

FIG. 2 shows the pellet 35 in greater detail as being in integral,one-piece generally cylindrical unit with a head portion 37 having acentral portion of maximum diameter which tapers downwardly on one sideto the end of the pellet and on the other side to its reduced diametercenter. The diameter of the pellet increases gradually from its centerto a base portion 41 having a flat end wall. If desired, the end wall ofthe base 41 can be cur-ved, or the entire base flattened to a moreelliptical shape and curved to more readily conform to the general shapeof the area between the screw thread crests.

During manufacture, that is either before or after the envelope isfastened to the base, the head 37 of the pellet is inserted from theoutside of the base into the hole 30 and it is pushed in until the edgeof the base wall surrounding the hole contacts the body portion. Asseen, the inwardly sloping Wall of the valley between the two crests ofthe screw thread generally conforms to the tapering shape of the pelletbody. The maximum diameter portion of the pellet head 37 is slightlylarger than the diameter of the hole 30. This provides a pressure orsnap t for the pellet into the hole and prevents the pellet from fallingout. The body portion 41, being of larger diameter than the hole 30,prevents the pellet from being pushed into the'base.

`PIG. 3 shows the base of a lamp made in accordance with the subjectinvention screwed into a socket. As can be seen, the material of thepellet 35 is compressed by the screw threads of the socket. Since thehead of the pellet preferably extends only to, or slightly beyond, thecrest of the thread and since the pellet preferably occupies only arelatively small portion of the total eX- ternal area of the base, thelamp can be easily screwed into the socket and the pellet does notinterfere with the electrical contact between the base and socket. Also,materials such as nylon and Tellon are relatively smooth and provide agood bearing surface.

The compressed material of the pellet is wedged between the matingthreads of the base and socket. Due to this, and also due to the forceexerted by the material in trying to return to its normal shape, thelamp is securely locked to the socket.

FIG. 4 shows a socket having a pellet 35 inserted in a hole 30a thereinbetween two screw threads, the conductive portion of the socket beingheld in an insulated housing 50. This conguration has an advantagebecause there are a number of places where the pellet can be inserted,as compared to the base of a lamp which has limitations such as theglass and the base lead wires.

While the pellet can be inserted either in a lamp base or a socket, itshould be understood that several advantages accrue to both embodiments.In the case of the lamp, the pellet can be inserted in the base of anylarnp and this lamp locked tight to any socket of any fixture. Ofcourse, this requires one pellet for each lamp and the additionalmanufacturing step of making a hole in the lamp base. On the other hand,when a pellet is used in a socket, all lamps used in that particularsocket will be ad-vantageously locked in. Also, as should be apparent, apellet can be used on both the lamp base and the socket members.

While the invention has been shown with a screw type base, it should beunderstood that it also can be advantageously used with other types ofbases, e.g., bayonet.

While preferred embodiments of the invention have been described above,it will be understood that these are illustrative only, and theinvention is to be limited solely by the appended claims.

What is claimed is:

1. The combination of an electric lamp having a base member and a socketmember to which said base member is to be secured to make electriccontact therewith,

a piece of resiliently compressible material, means for securing thepiece of material to one of said base and socket members to engage theother of said members when the lamp is in the socket, said piece ofmaterial shaped to permit normal insertion and removal of the lamp basefrom the socket and being compressed between said two members when thelamp base is within the socket to securely hold the lamp to the socket.

2. The combination of claim 1 wherein said piece of material is in theshape of a pellet and said securing means comprises the wall of one ofsaid members formed with a hole through which the pellet protrudestoward the wall of the other member, said pellet being held by the wallof said one member surrounding the hole formed therein.

3. The combination of claim 2 wherein the wall of the socket member hasthe hole formed therein for holding the pellet.

4. The combination of claim 2 wherein the wall of the lamp base memberhas the hole formed therein for holding the pellet.

5. The combination of claim 4 wherein the base member is of the screwtype and the hole is formed in said base between adjacent crests of thescrew thread in which the piece of material is held.

6. The combination of claim 3 wherein the socket member is of thethreaded type for a screw type lamp, and a hole is formed in a wall ofsaid socket in which the piece of material is held.

7. The combination of claim 5 in which said piece of material is in theshape of a pellet having a reduced diameter tip portion which permitsthe pellet to be inserted into the wall from outside of the lamp base.

8. The combination of claim 7 in which said piece of material is in theshape of a pellet having a reduced diameter intermediate portion whichpermits the pellet to be held within said hole by the surrounding wall.

References Cited UNITED STATES PATENTS 1,082,397 12/1913 Blass 339-842,212,728 8/1940 Blood 339-93 3,000,231 9/ 1961 Cochran 74-502 FOREIGNPATENTS 344,730 11/ 1936 Italy.

MARVIN A. CHAMPIIO'N, Primary Examiner.

JOSEPH H. M. MCGLY-NN, Assistant Examiner.

U.S. C1. X.R. 285-404; 339-93

